Lighter-than-air aircraft



' 1,637432 1927' B. N. WALLIS ET AL LIGHTERrTHAN-AIR AIRCRAFT Fiied'Dec. 17, 1925 1,637,432 PATENT OFFICE; J

Patented Aug. 2, 19 27. c

UNITED STATES BARNES NEVILLE WALLIS AND CHARLES, DENNI STO N BURNEY, OFWESTMINSTER, LONDON, ENGLAND, ASSIGNORS TO AIRSHIP GUARANTEE'COMPANY,LIMITED, OF

" LONDON, ENGLAND. I

LIGHTER-THAN- Application filed December 17, 1925, Serial No.

, This invention relatesto lighter-than-air In "H! as is the case whenan "aircraft. i I i I I Much attention has, in recent years, beendevotedto the problem of increasing the speed of air-ships, and,in'order that this may be economically accomplished, it is desirable, tointroduce devices for reducing their headresistance. The principalmethod of obtaining improvement in the latter respect has been to makethe hull of the airship of a so-called streamline shape, andconsiderable data are now available showing the general form thatshouldbe fol-' lowed in designing the lines of thebody orhullof the airship oraerostat. I i

For example, it is known that a body having a ratio oi? overall lengthto maximim diameter of 4 or 5 to l will oiier as low a resistance topropulsion through the air as anyship yet produced, provided thefollowing proportions are generally fmain .tained; (a That the head orfront portion should be approximately two diameters long, ,at whichdistance fronrthe nose the maximum diameter of the body should occur,and

should consist of a semiprolate ellipsoid that is to saythe vsolidformed by the rotation of a semiellipse about its major axis and '(b)that the tail or after portion should-be ape proximately 2% or diameterslongrheasured from the place at which it joins the ,head portion. I

Such a form'ha'ving been obtained, it is found,however, that the shapeappears "to be "too sensitive to external disturbances whenreproduced ona full sized ship.

It must beunderstood that at the present time it is customary to locatethe mainloads of lighter-than-air aircraft such as thecontrol,;passenger, andengine cars atgvarious points along or projectbeyond "or aerostat they form protuberances which interfere with thestreamline flow around and along the hull or body, and thusset'up,discontinuousflow and turbulence. I I I This turbulence ismost-serious when originated in the region-of thehead portion, i i thecars, or other causes of turbulence,are situated forward ofthe maximumdiameter of the ship. i Further, it is found that the lower the resistance of the bare hull or body, the'more serious dosuch disturbancesbecome so that beneath the hull, and as they, the contour of the airshipAIR AIRCRAFT.

in the past it may even have been preferable to construct a hullactually having a higher head resistance in itself, in order that thetotal resistance of the ship when fitted with cars might be, in theaggregate, less than that of asensitive shape when fitted with anidentical arrangement of cars.

According to the present invention the front part of an airship, orother lighterthanair aircraft of torpedo-like configuration, is kept, upto the maximum diameter thereof, free or substantially free of externalprotuberances, such as cars, struts, wiring,'etc. To this end the mainloads, such the observation, passenger, and engine cars are eitherwholly located within the outer cover of the airship or aerostat so thatthey do not protrude beyond the contour thereof or else they arelocatedabaft the imaxzmum diameter of the ship, where the tubulence setup is not of a serious nature.

rllternatively, a combination of these two methods may be employed, sothat the ship or aerostat iskept free or substantially free ofprotuberances up to a point abaft the maximum diameter thereof. a i

It has been found that by adopting such an arrangement of the main loadsand/0r external protuberances the total resistance is Very considerablyreduced; it may in certain cases be reduced by as much as 30%. -Furthermore, this disposition of the main loads within the externalstreamline or contour, or abaft the maximum diameterfo'f the airship oraerostat, also enables the most approved streamline configuration to beadopted, while retaining the advantages of reduced head resistance,sensitiveness to con trol and navigability which result from the use ofa fine streamline shape.

In the case of a rigid airship the main protuberances, such as theobservation or control car and the passenger and engine cars, may belocated within the contour or outer streamline of the ship, or certainof the main loads, such as the observation and passenger cars, may. belocated within the outer streamline of the ship, while the engine carsmay be located abaft the maximum diameter of the airship inthe Zone ofnegative pressure." The ship may be of streamline con'figurationand havea length to diameter ratio of 4 or 5 to 1 or as may be found desirable.The nose of the ship up to the first transverse frame may itsell be I arigid airship constructed according to the present invention.

Figure 2 is a cross section of part of one side of the airship thesection being taken in the way of the coaches. c

Figureis a part sectional plan view of Figure 1 showing the frontportion of the airship up to the maximum diameter theren is the outercover or enveloping surface of the airship. B. B are the longitudinalgirders and B E the transverse frames. C is the mesh wiring whichencloses the bags the latter being locatedas is custonr ary between eachpair of transverse frames B B, the mesh wiring being preferably of thekind described in English Patent No 233,020 in order to allow tangentialloading to be resorted to. D is the mesh wiring on the face of each ofthe transverse frames, and E is cord netting located transversely of theairship between each pair of gas bags, the

cord netting being connected to the frames by flexible steel cables E EF, F are the coaches which are preferably suspended from the frameworkof the airship and have their parts constructed and arranged in themanner described in our co-pending English application No." 238,981. Itwill be observed that the coaches are located entirely within thestreamline or outer enveloping surface A of the airship. G. G arecorridors located on each side of the airship and establishingcommunication between a compartment H at the nose of the airship and thepassenger coaches. It will be observed that staircases I, I are carriedby the suspended coaches F, F and that the corridors G. G on each sideof the airshipgive access to thesaid staircases. The; corridors G, G arepreferably also suspendedfrom the framework of the airship in the mannerdescribed in the specification of our English Patent No. 233,021. Thecorridors G, G by which access is obtained to the passenger coaches F,

F extend beyond the coaches (see Figure l) was to allow the crew to haveaccess to all parts of the airship, and additional passages may alsobeprovided in the interior of the transverse frames as described in ourEnglish patent specification No. 233,021. The compartment H' at the noseof the airship not only allows the passengers to enter and leavetheairship through a transversely disposed corridor 71, (see Figure 3)which esta lishes communication between the exterior and the corridorsG, G, but is also employed as an observation and control car; obser'ation posts being pro *ided, for exampic at the points if, 7L1. In thearrangement shown, the compartment H is located between an auxiliaryframe H situated between the nose of the airship and the first maintransverse frame B The maximum diameter of the airship occurs at thepoint X X, and it will be observed that the only protuberances beyondthe streamline or outer I envelope of the, airship are the engine carsL, L and the usual control fins K, K, and that these are located beyondthe maximum diameter thereof. Consequently, the airshipup to the,maximum diameter thereof is kept entirely free of the usual externalprotuberances, such as the control or observation station, the coachesfor the passengers and crew, and the engine cars.

The transyerse and longitudinal frames may be constructed in the mannerdescribed in our English Patent No. 233,021. Furthermore, and in orderto avoid distortion of the contour or external streamline due toflapping of the outer cover, which flapping as is well known, resultsusually from deterioration in the dope used to stiffen the cover tautalso has the advantage of ventilating the airship v withoutnecessitating the use of external protuberances, while the gas pressureof the internal gas bags may also be relieved by valves which do notprotrude beyond the contour or external streamline of the airship. I

llhat we claim and desire to secure by Letters Patent of the Unitedtates is An airship comprising a front portion consisting of asemi-prolate ellipsoid approximately2diameters long at which distancefrom the nose the maximum diameter of the airship occurs, and arealportion which is approximately 2 or 3 diameters longineasured fromtheplace where it is joined tothe front portion, said front portion up tothe maximum diameter of the airship being free or substantially freefrom external protuberances.

BARNES NEVILLE WALLIS. onanrns DENNISTON simmer.

